Prognosis for patients with heart failure and reduced ejection fraction with and without diabetes: A 7 year nationwide veteran administration analysis

Objective: Evidence suggests diabetes mellitus is an independent risk factor for adverse cardiovascular events in patients with heart failure. As a result, we sought to compare mortality in patients with heart failure with reduced ejection fraction (HFrEF) with and without diabetes.

Research design and methods: The Veteran Affairs Hospitals' databases were queried to identify all veterans diagnosed with HFrEF from 2007 to 2015. From the overall sample of 165,159 veterans, 41,120 patients with diabetes were matched by their propensity scores (without replacement) 1:1 to non-diabetic patients. To estimate the association between diabetes (Type 1 and 2) and overall mortality of HFrEF patients, a Cox proportional hazard model was used on the matched sample and controlled for patient characteristics for a mean follow up of 3.6 years (standard deviation ±2.3).

Results: In a matched sample of 41,120 veterans with HFrEF with and without diabetes, those with diabetes and HFrEF were more often on guideline-directed medical therapy than those without diabetes. In the matched cohort, the mortality risk for patients with concurrent HFrEF and diabetes was 17.7% at 1 year and 74.3% at 5 years, whereas the mortality risk for those without diabetes was 15.3% at 1 year and 69.2% at 5 years. After controlling for patient characteristics such as age, sex, body mass index, heart rate, medical therapies, comorbidities, medications, low-density lipoproteins, high-density lipoproteins, we found that patients with diabetes compared to those without had a significantly increased risk of mortality (HR: 1.85, 95% CI: 1.77-1.92, p < 0.001).

Conclusions: Diabetic HFrEF patients have a higher risk of mortality than non-diabetic HFrEF patients despite controlling for medical therapies and comorbidities.